That's because it is a phone booth. Teledisko is a full-service discotheque in a tiny, refurbished phone booth. From the outside, select your music. Then you and your friends step inside. There's a stereo, a mirror ball, strobe lights, and a fog machine. The booth has a built-in camera that prints out photos of your party when you're done.
It's a nifty art project, but I could also see Teledisko succeeding as a business. Large parties could rent one as a gimmick. Check out this video to see the appeal:
There are two Telediskos set up in Berlin and a third available for rent.
-via Pop-Up City